Some guest drivers may not configure disabled virtio queues.

In this case, the vhost management never notifies the application and
the vDPA device readiness because it waits to the device to be ready.

The current ready state means that all the virtio queues should be
configured regardless the enablement status.

In order to support this case, this patch changes the ready state:
The device is ready when at least 1 queue pair is configured and
enabled.

So, now, the application and vDPA driver are notifies when the first
queue pair is configured and enabled.

Also the queue notifications will be triggered according to the new
ready definition.

Signed-off-by: Matan Azrad <redacted>
---
 lib/librte_vhost/vhost.h      |  1 +
 lib/librte_vhost/vhost_user.c | 55 +++++++++++++++++++++++++++++--------------
 2 files changed, 38 insertions(+), 18 deletions(-)

diff --git a/lib/librte_vhost/vhost.h b/lib/librte_vhost/vhost.h
index 17f1e9a..8a74f33 100644
--- a/lib/librte_vhost/vhost.h
+++ b/lib/librte_vhost/vhost.h

@@ -151,6 +151,7 @@ struct vhost_virtqueue {
 	int			backend;
 	int			enabled;
 	int			access_ok;
+	int			ready;
 	rte_spinlock_t		access_lock;
 
 	/* Used to notify the guest (trigger interrupt) */

diff --git a/lib/librte_vhost/vhost_user.c b/lib/librte_vhost/vhost_user.c
index 8d8050b..b90fc78 100644
--- a/lib/librte_vhost/vhost_user.c
+++ b/lib/librte_vhost/vhost_user.c

@@ -228,6 +228,21 @@
 	dev->postcopy_listening = 0;
 }
 
+static void
+vhost_user_notify_queue_state(struct virtio_net *dev, uint16_t index,
+			      int enable)
+{
+	int did = dev->vdpa_dev_id;
+	struct rte_vdpa_device *vdpa_dev = rte_vdpa_get_device(did);
+
+	if (vdpa_dev && vdpa_dev->ops->set_vring_state)
+		vdpa_dev->ops->set_vring_state(dev->vid, index, enable);
+
+	if (dev->notify_ops->vring_state_changed)
+		dev->notify_ops->vring_state_changed(dev->vid,
+				index, enable);
+}
+
 /*
  * This function just returns success at the moment unless
  * the device hasn't been initialised.

@@ -1306,27 +1321,31 @@
 
 	return rings_ok &&
 	       vq->kickfd != VIRTIO_UNINITIALIZED_EVENTFD &&
-	       vq->callfd != VIRTIO_UNINITIALIZED_EVENTFD;
+	       vq->callfd != VIRTIO_UNINITIALIZED_EVENTFD &&
+	       vq->enabled;
 }
 
+#define VIRTIO_DEV_NUM_VQS_TO_BE_READY 2u